Research On The Noise Sensitive Characterization Technique For Radiation Damage In Polysilicon Conductive Materials

With the development of aerospace technology, the kinds of electronic materials and devices used in space environment increased constantly. Polysilicon conductive material is an important basis material in integrate circuits and photovoltaic industry, its performance degradation has a tremendous impact on the reliability of aerospace electronic devices and systems in irradiative environment. Conventional electrical characterization of polysilicon conductive materials radiation damage is insensitive; however, noise is closely related to the internal defects in materials, it can be a faithful reflection of the internal radiation damage. This paper research on noise characterization technology for radiation damage, it can be used in polysilicon conductive materials and device.Considering the practical application environment of polysilicon conductive material, we design four kinds of resistor samples with a total number eleven. Those samples almost contain every application of polysilicon conductive materials in IC. They are designed as four-terminal test structure, which can be a faithful reflection of the polysilicon conductive materials radiation damage and convenient for noise testing. Based on the Well-designed 60Coγirradiation experiments the electrical and noise parameters are tested. Through analyses and comparison, the damage mechanism of polysilicon resistor samples are given, and optimum noise sensitive characterization parameters of polysilicon conductive materials which suffer from radiation damage are presentedThe 1/f noise models available for polysilicon conductive materials were based on mobility fluctuation and carrier number fluctuation mechanism, respectively. However, according to the transmission physical image in polysilicon conductive materials, carriers will be captured by the defects which gather around grain boundaries, it will result in the carrier number fluctuations, these captured carriers will modulate the potential barriers of grain boundaries, it will cause carrier mobility fluctuations. Therefore, it is imperfect to consider a single fluctuation. In this paper, we consider carrier number change which caused by the defects capturing and emitting around grain boundary is related to grain boundary potential barriers. Based on the dual mechanisms we establish a unified 1/f noise model for polysilicon conductive materials. By introducing the radiation damage coefficient, we establish the 1/f noise characterization model for polysilicon conductive materials. Finally, based on the noise characterization technique, we presented the irradiation failure criterion and basic measurement process of polysilicon conductive materials.